Definition of "Niche Complementarity" What does "Niche Complementarity" mean? * * * On this website they define "Niche Complementarity" as: > The tendency for coexisting species which occupy a similar position along one niche dimension I don't quite understand this definition. The tendency to do what? * * * Notes: * I know what is an ecological niche and therefore what is a niche dimension. There is no need to define this. * I am particularly interested in the use of this concept in speciation and adaptive radiation.

As it has been said by @A.kennard in the comments, the definition the OP found is not complete. The full definition on the link he gave (here) is:

Niche Complementarity:

> The tendency for coexisting species which occupy a similar position along one niche dimension to differ along another.

The concept that two competing species will tend to evolve different evological niche is called character displacement. The definition from wikipedia is

> Character displacement is the phenomenon where differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are minimized or lost where the species’ distributions do not overlap.